Process for preparing solutions of cellulose and for the production of cellulose products from such solutions.



itjli lllli ldlfr git Tillie} i t 1 W1? 1; -a lists U a il ERNST BERL, 0F TUBIZE, BELGIUM.

PROCESS FOR PREPARING-SOLUTIONS OF CELLULOSE AND FOR THE PRODUCTION U13 GELLULOSE PRODUCTS FROM SUCH SQLUTI ONS.

No Drawing.

To uZZ whom may coucem Be it known that l, Euns'r Emit, a subject of the Emperor of Austria-Hungary, resid ing at Tubize, in the Kingdom of Belgium, have invented certain new and useful improvements in the process for preparing solutions of cellulose and for the productionof cellulose products from such. solutions, of which the following is a specification.

My invention relates to an improved process for preparing solutions of cellulose with sulfuric acid and for the production of cellulose products from such solutions.

It is known that concentrated sulfuric acid of certain strengths is capable of exerting a swelling or solvent action on cellulose and its closely allied products, hereinafter called. ccllulosie materials. This property has been turned to use in the manufacture of parchment, in acid mereerizi'ng and so forth. Langhans (German Patent 72,572) attempted to make use of the solvent action of sulfuric acid on cellulose for preparing substances capable of spinning and squirt ing. By Working according to the 111strucions of this patent a substance is obtained which readily becomes fluid, in which liquid large quantities of unattached cellulose are found. It is therefore very dillicult to filter such products. If the coagulation be undertaken with Water as stated in this patent then products of small stability are obtained. On the other hand according to my invention valuable spongy masses and solutions can be obtained when using" allulose or its closely allied derivatives for the manufacture of articial threads,'tulle, filmslind plastic masses, if the temperature be kept continuously very low and concentrated sulfuric acid of: certain strength (-77% H 30 be employed when making the spongy mass. Under these conditions the decomposing and de'hydratinb action of the sulfuric acid onthe cellulose is restricted to a practically harmless degree. Naturallythis advantageous influence of low temperature must be maintained during the process of coagulation. Otherwise thadecomposing action of the sulfuric acid predominates, resulting in the prepared products lacking in that the coagulation temperature must be nearly the same as or'lower than the torn perature for producing the spongy mass to obtain products of value. Consequently such Specification of Letters Patent.

stability; It has been proved" Patented Dee. 36 1913.

Application filed June 3, 1913. Serial No. WL-QQZ.

some time. A viscous mass is obtained from which the confined air can be exhausted in occur). After filtering coagulation is caused by mmersion in 50% alcohol cooled to Ezarople ll: One part mercerized cotton is thoroughly intermixed with 12- parts sulacid of in a kneading machine at a temperature not exceeding -l5 C. till it has swollen up-toa viscous mass. Coagulation is obtained by a very strongly cooled aqueous solution of methyl alcohol.

Example Ill: Hydrocellulose is digested with sulfuric acid as described in Examples l. and H till a homogeneous viscous mass is obtained; coagulation is brought about by 95% sulfuric acid cooled almostto its freezing point.

Example IV: Finely divided carefully dried wood cellulose is likewise digested with strongly cooled 65% sulfuric acid. till a homogeneous mass is obtained and is coagulated by a solution of ammonium sulfate cooled to -18 C.

Example V: l/Vastes of artificial silk are placed in sulfuric acid of 60% cooled to a .remperature of about -10 to 15 C. and

are then digested at said low temperature till a homogeneous mass is obtained; the coagulation is then obtained according to one of the already stated methods.

What I claim is:

1. A process for producing solutions of cellulose said process consisting in treating a cellulose-containing material with sulfuric acid at a ten'ugerature not exceeding -10 C.

2. A. process for producing solutions of cellulose, said process consisting in treat then subjecting the solution-tothe action of ing a cellulose-containing material with sulfuric acid of 60-77% H SO at a temperature not exceeding -l C.

- 3. A process for producing solutions of cellulose and obtaining cellulose products from such solutions, said process consisting in treating a cellulose-containing material with sulfuric acid of 6077% H 80 at a temperature not exceeding C:

a coagulating liquid at a temperature not exceeding 10; C;-

5. A process for-converting cellulosic ma- 1 terial into a form suitable for the manufac- 'ture of artificial silk tulle, films and the like, said processconsisting in treating the cellulosic material with sulfuric acid of 60-77% HgSO at-a' temperature nOt'eX- ceeding '-l0;G, and then coagulating the solution while maintaining said low-temperature, 1 e. 9 Y

6. A rocess forconverting cellulosic material into a form suitable for-the manufacture of artificial 'silk,- tulle, films and the like said process consisting in digesting the cellulosic material with sulfuric acid of 60-77% H 80 at a temperature not exceeding 10 C. and then treating the solution with a coagulating agent adapted to be cooled to a temperature not exceeding 1.0 (3., whereby the solution of cellulose is caused to coagulate.

7. A process for producing solutions of cellulose, consisting in treating a cellulosecontaining'material with a solvent at a temperature not above l0 C.,'said solvent normally dehydrating cellulose.

8. A process for producing solutions of cellulose, consisting intreating a cellulosecontaining material with sulfuric acid at a temperature at which the dehydrating action of sulfuric acid on cellulose is practi-' cally nil.

'9. A process forproducing solutions of v cellulose, consisting in treating a cellulosecontaining material with a solvent which normally dehydrates cellulose at a temperature at which substantially no dehydration .of the cellulose takesplace.

In testimony whereof I have afiixed my signature in presence of two Witnesses.

' v ERN ST BERL. QWitnesses: v

J Aoouns Brim, I 'C. RNASMITLE'. 

